Returns the world eye angle pitch of the owner, in a range of values from -0.0056179768 (straight down) to 1.0056179768 (straight up).
When root owner is enabled, the owner is the player (or whatever entity the outfit is applied to). When it's disabled, the owner is the proxy's parent, or its target entity.
A value of 0 corresponds to 89° below the horizontal, and 1 corresponds to 89° above the horizontal.
Player cameras cannot normally go beyond these values. Other entities can.
To make 0 and 1 actually correspond to +/-90°, add .0056179768, then divide the sum by 1.0112359536.
((owner_eye_angle_pitch() + .0056179768 ) / 1.0112359536)
This is used instead of owner_eye_angle_pitch() for entities other than the player to get correct 0 to 1 values when 'looking' straight up or down.